This competitive renewal proposal describes the accomplishments of the University of Michigan Reproductive Medicine Network (RMN) site and the qualifications and experience of the research team comprised of collaborative faculty from Reproductive Endocrinology, Urology, Medical Endocrinology, and Biostatistics. The University of Michigan Center for Reproductive Medicine includes 6 Board Certified clinicians in Obstetrics and Gynecology, Reproductive Endocrinology or Urology. Collaborating within the Center is a biostatistician with over 20 years of clinical trials experience and 2 Medical Endocrinology faculties who provide expertise on obesity and metabolism and unique metabolomics research resources. We have partnered with Michigan State University to serve as an Ancillary Site for enrollment into clinical trials extending the subject catchment areas to Western and Northern Michigan and surrounding states. In the previous funding period, the University of Michigan site participated actively in the inception, selection, design, and review of four clinical protocols, te establishment of the RMN tissue and DNA repositories and birth outcomes database. The University also provided leadership in the evaluation and treatment of male infertility, recruited and mentored a Clinical Research/Reproductive Scientist Training (CREST) scholar to develop a successful ancillary recruitment site, and contributed to numerous RMN manuscripts and committees. We bring to the RMN the valuable resources of the NIH supported Michigan Clinical Research Unit, Michigan Nutrition Obesity Research Center, and Michigan Regional Comprehensive Metabolomics Resource Core, as well as the full support of the Departments of Obstetrics and Gynecology, Department of Urology, and Division of Metabolism, Endocrinology and Diabetes at the University of Michigan and the Women's Program at the Ann Arbor VA Medical Center. In addition, Michigan State University brings full support of its statewide Department of Ob/Gyn, numerous University Research cores, and experience in conducting clinical trials in women's health. The concept protocol addresses treatment of infertility associated with obesity-related ovulatory dysfunction. It investigates the impact of intensive preconceptual weight loss on reproductive outcomes and response to clomiphene citrate, and assesses if pretreatment or treatment-induced alteration in clinical or metabolomics profiles predicts reproductive outcomes. In summary, the research investigators at the University of Michigan Center for Reproductive Medicine and associated Centers and Departments provide an unparalleled environment to perform multicenter clinical trials. The University has been an effective site in the current RMN, and is fully prepared to recruit, participate, and lead in the fll breath of RMN activities in the next stage of this important program.